Resource-limited Areas Research Articles

Compact highly sensitive photothermal RT-LAMP chip for simultaneous multidisease detection

Developing instant detection systems with disease diagnostic capabilities holds immense importance for remote or resource-limited areas. However, the task of creating these systems—which are simultaneously easy to operate, rapid in detection, and cost-effective—remains a challenge. In this study, we present a compact highly sensitive photothermal reverse transcriptase–loop-mediated isothermal amplification (RT-LAMP) chip (SPRC) designed for the detection of multiple diseases. The nucleic acid (NA) amplification on the chip is achieved through LAMP driven by either LED illumination or simple sunlight focusing. SPRC performs sample addition and amplification within a limited volume and autonomous enrichment of NA during the sample addition process, achieving a limit of detection (LOD) as low as 0.2 copies per microliter. Through 120 clinical samples, we achieved an accuracy of 95%, with a specificity exceeding 97.5%. Overall, SPRC has achieved promising progress in the application of point-of-care testing (POCT) by using light energy to simultaneously detect multiple diseases.

Chemical Heating for Minimally Instrumented Point-of-Care (POC) Molecular Diagnostics

The minimal instrumentation of portable medical diagnostic devices for point-of-care applications is facilitated by using chemical heating in place of temperature-regulated electrical heaters. The main applications are for isothermal nucleic acid amplification tests (NAATs) and other enzymatic assays that require elevated, controlled temperatures. In the most common implementation, heat is generated by the exothermic reaction of a metal (e.g., magnesium, calcium, or lithium) with water or air, buffered by a phase-change material that maintains a near-constant temperature to heat the assay reactions. The ability to incubate NAATs electricity-free and to further to detect amplification with minimal instrumentation opens the door for fully disposable, inexpensive molecular diagnostic devices that can be used for pathogen detection as needed in resource-limited areas and during natural disasters, wars, and civil disturbances when access to electricity may be interrupted. Several design approaches are reviewed, including more elaborate schemes for multiple stages of incubation at different temperatures.

Detection of tuberculosis using cough audio analysis: a deep learning approach with capsule networks

PurposeTuberculosis (TB) is a widespread infectious disease that requires early detection for effective treatment and control. This study aims to improve TB detection using cough audio analysis, comparing the performance of capsule networks to other deep learning models.MethodsWe used cough audio recordings from 1105 individuals with a new or worsening cough for at least two weeks, totaling 9772 recordings. These recordings were processed into spectral images, and HOG features were extracted. Various models, including Capsule Networks + FCNN, CNN, VGG16, and ResNet50 were trained and evaluated.ResultsCapsule Networks + FCNN achieved the best performance with an accuracy of 0.97, sensitivity of 0.98, specificity of 0.96, F1 score of 0.97, and precision of 0.97, outperforming other models. This attribute is due to the model’s ability to learn complex features from spectral images.ConclusionsThis study concludes that Capsule Networks are more effective than typical CNN-based models in diagnosing TB from cough audio. This suggests that advanced deep learning frameworks could significantly enhance TB screening accuracy, especially in resource-limited areas.

Rapid and multiple visual detection of Fasciola hepatica in feces via recombinase polymerase amplification integrated with CRISPR/Cas12a technology

Fasciola hepatica is a foodborne zoonotic parasite causing significant economic losses and impacting human and livestock health in resource-limited regions. We developed a rapid, reliable, and sensitive detection method combining recombinase polymerase amplification (RPA) with CRISPR/Cas12a, allowing visualization with the naked eye or a fluorescence reader. Multiple visual methods were used to analyze the assay results. Fluorescence signals were collected using a fluorescence reader or observed under UV or blue light. Lateral flow strips (LFS) were used for visual detection. Among seven primer pairs and three CRISPR RNA (crRNA) screened, F1/R1 and crRNA3 were optimal. The Cas12a reaction buffer was optimized with 50 mM Tris-HCl and 80 mM NaCl, with an RPA reaction time of 20 min. The assay showed high specificity and excellent sensitivity for F. hepatica, detecting 0.122 copies/μL with fluorescence and 8.6 copies/μL with LFS. Testing of 143 sheep and 43 human fecal samples showed 98.39 % consistency with qPCR and nested PCR, with prevalence rates of 52.45 % and 18.6 % in sheep and humans, respectively. Our assay offers substantial potential for point-of-care testing in resource-limited areas, addressing the need for rapid and accurate diagnosis of F. hepatica.

COMPARISON OF YIELD AND QUALITY OF CIRCULATING CELL-FREE DNA FROM K2EDTA AND K3EDTA COLLECTIONS IN HEALTHY SUBJECTS

Background: Circulating cell-free DNA (cfDNA) is a biomarker for various clinical applications, including detecting and monitoring cancer. However, blood collection tubes can affect the yield and quality of cfDNA. Since specific cfDNA collection tubes are costly, K2EDTA and K3EDTA anticoagulant tubes are alternatives in routine clinical laboratories. Objectives: This study aimed to compare the efficiency of cfDNA extraction from plasma collected in K2EDTA and K3EDTA tubes and evaluate implementation for molecular diagnostics. Methods: Blood samples from 38 healthy subjects were collected in K2EDTA and K3EDTA tubes that were processed within 2 hours. The extracted cfDNA was measured and performed using SYBR Green-based qPCR for three endogenous reference genes (GAPDH, HPRT1, TFRC). The cfDNA yield and the amplification efficiency of these genes were compared between K2EDTA and K3EDTA tubes using the Mann-Whitney U test. Results: There were no significant differences in cfDNA concentration between K2EDTA and K3EDTA tubes (p=0.051). However, qPCR analysis revealed significantly higher copy numbers of TFRC and HPRT1 in K2EDTA tubes than in K3EDTA tubes (p<0.05). No significant difference was found for GAPDH. Conclusion: The results indicate that K2EDTA and K3EDTA tubes are an alternative option for cfDNA analysis if samples are processed quickly after a blood draw, which offers flexibility and cost savings in resource-limited areas.

Factors associated with teenage pregnancy among refugees in Palabek refugee settlement, Northern Uganda

BackgroundGlobally, teenage pregnancy is a public health problem. Low- and middle-income countries in the Sub-Saharan region are more affected with teenage pregnancy. It is worse with teenage girls who have other vulnerabilities like living in refugee camps. However, there is little information about teenage pregnancy in refugee camps especially in resource limited areas like Northern Uganda.ObjectiveTo determine the prevalence and the factors associated with teenage pregnancy among refugees in Palabek refugee settlement, Northern Uganda.MethodsThis was a cross-sectional study conducted among teenage girls in Palabek refugee settlement in Northern Uganda. The study estimated a total sample size of 316 teenage girls and they were sampled using systematic random sampling. Data was collected using researcher administered questionnaire. Conditional logistics regression was employed to identify the associated factors for teenage pregnancy.ResultsA total of 306 teenagers participated in the study with a response rate of 98.6%. The study showed that the prevalence of teenage pregnancy among teenage girls in Palabek refugee settlement, Northern Uganda was 41.2%. The factors associated with teenage pregnancy among teenage girls in Palabek refugee settlement included: being in the 15–19 years age group (AOR = 6.3, 95%CI: 1.8–22.8), not being in school (AOR = 5, 95%CI: 2.3–10.9), not being married (AOR = 0.2, 95%CI: 0.1–0.5), delayed sexual debut (AOR = 2.4, 95%CI: 1.1–5.5), having multiple sexual partners (AOR = 0.3, 95% CI: 0.1–0.7), alcohol use (AOR = 6.7, 95%CI: 2.2–18.4), being aware of sexual reproductive health services (AOR = 0.4, 95%CI: 0.2–0.9), and having divorced families (AOR = 2.4, 95% CI: 1.2–4.9).ConclusionStudy results reveal that 4 in 10 teenage girls in Palabek, Northern Uganda, are pregnant, influenced by individual, community, and health system factors. This highlights vulnerabilities in refugee camps, urging prioritization of sexual and reproductive health for adolescent girls in refugee camps.

Development and preliminary assessment of the iFIND TBR: all-in- one molecular diagnostic assay for rapid detection of Mycobacterium tuberculosis and rifampicin resistance

IntroductionEarly and accurate diagnosis of tuberculosis (TB) is crucial for initiating timely treatment and preventing new infections. In this study, we introduced the iFIND TBR assay, an automated all-in-one tuberculosis detection approach that simultaneously detect Mycobacterium tuberculosis (MTB) and rifampicin (RIF) resistance.MethodsThe limits of detection (LOD), sensitivity, specificity, and RIF-R rpoB mutation detection of the iFIND TBR were tested on Mycobacterium tuberculosis DNA or sputum samples spiked with known numbers of M.tuberculosis H37Rv. Frozen clinical samples from patients suspected of having TB were also tested.ResultsThe LOD of the iFIND TBR for MTB detection were 13.34 CFU/ml (95% CI, 11.71-16.47), and for RIF resistance was 109.79CFU/mL (95% CI, 95-138.19). The iFIND TBR assay accurately distinguish MTB strains from non-tuberculous mycobacteria (NTM) without any cross reactivity. Testing on 157 clinical sputum samples, compared with the bacteriologically TB standard, the overall sensitivity and specificity of the iFIND TBR was 100% (95%CI, 94.64, 100) and 85.29% (95% CI, 74.61, 92.72), respectively. When assessing RIF susceptibility, the iFIND TBR achieved a sensitivity of 98.15% (95% CI, 90.11–99.95) and a specificity of 85.71% (95% CI, 67.33–95.97), compared with phenotypic drug susceptibility testing. Discordant RIF susceptibility results were more frequently observed in samples exhibiting heteroresistance.DiscussionThese findings demonstrate that iFIND TBR assay performs well in detecting TB and RIF resistance, and shows promise as a point-of-care tool in resource-limited areas.

Distance-Based Fluorescent Immunosensor for Point-of-Care Test of Illegal Additives through the Gas-Producing Nanozyme.

The colorimetric point-of-care test (POCT) offers a rapid and efficient method for detecting specific targets in real samples. However, traditional colorimetric methods often rely on complex signal amplification techniques or electronic devices to enhance detection sensitivity, which can inadvertently increase both cost and time, thus contradicting the fundamental goals of visual detection methods. Here, we presented a distance-based fluorescent immunosensor that utilized a gas-producing nanozyme for continuous gas production reaction as a signal. Specifically, the SOM-ZIF-8@Pt nanozyme catalyzed the production of O2 from H2O2 to cause an obvious increase in the pressure within a sealed chamber, thus driving the production of H2S to quench the fluorescence of CsPbBr3 on the walls of the capillaries. Based on the competitive immunoassay, the fluorescence quenching lengths were relative with the concentration of aminopyrine in the range from 0.2 to 20 ng/L; thus, the fluorescent POCT-based homemade device was realized through the amplification of distance-based signals facilitated by the continuous gas production reaction. This strategy provides an effective way to realize POCT assays in resource-limited areas by transforming pressure variations into directly observable signals. Furthermore, distinguished by its high sensitivity, ease of operation, and portability, it also represents a significant advancement in biomedical diagnostics, particularly within home healthcare and clinical POCT.

Adherence to infection prevention practices and associated factors among healthcare workers in Northeastern Ethiopia, following the Northern Ethiopia conflict.

In resource-limited areas, especially in conflict-affected settings, managing the risk of hospital-acquired infections is difficult due to the destruction of essential facilities in healthcare settings. The study aimed to assess adherence to Infection prevention practices and associated factors among healthcare workers in Northeastern Ethiopia following the Northern Ethiopia conflict. A facility-based cross-sectional study was done with 408 healthcare workers. The survey data was collected using a structured questionnaire based on published articles. Data entry and analysis was done using Epi-Data version 4.6 and SPSS version 25.0, respectively. Binary logistic regression was used to determine the association between dependent and outcome variables, with a cut-off p value 0.05 at 95% confidence interval with a p-value less than 0.05 and a 95% confidence interval for determining factors associated with adherence to infection prevention practices among study participants. The study included 408 healthcare workers with a response rate of 96.7%. The majority of participants were women 206 (50.5%), married 250 (61.3%), Orthodox followers 211 (51.7%), and educational status of master holder and above with a master's degree or higher 177 (43.4%). Slightly more than half, 53.7% (219) of the respondents demonstrated safe infection prevention practices. Respondents who received training on infection prevention practices (AOR = 2.662, 95% CI: 1.361, 5.120) had an active infection prevention committee (AOR = 2.203, 95% CI: 1.359, 3.572), use infection prevention guidelines in working departments (AOR = 2.090, 95% CI: 1.013, 4.312), and access to adequate personal protective equipment (AOR = 2.773, 95% CI: 1.560, 4.929) were factors significantly associated with adherence to infection prevention practices. Overall, only half of the respondents practiced safe infection prevention practices. Receive training on infection prevention guidelines, presence of active infection prevention committee and working guidelines, and the availability of personal protective equipment were factors of infection prevention. Hence, essential facilities like Personal protective equipment, working guidelines should be supplied by donors.

Utility of a Smart Device Infrared Camera in Localizing Acute Pediatric Long Bone Fractures: A Pilot Study.

Musculoskeletal injuries are one of the top 10 reasons children present to the emergency department (ED). Infrared thermal imaging (IRT) is a noninvasive and nonradiating imaging modality that can detect subtle temperature differences. IRT may be used to detect the presence of musculoskeletal injury. This study aimed to assess the utility of a smart device infrared camera attachment's ability to localize acute pediatric long bone fractures in patients less than 5 years of age. This was a prospective pilot study comparing thermal imagery on an injured extremity to radiographs. All IRT images were obtained via an iPad with an infrared camera attachment. Using two different IRT images (Hi/Lo and Span and Level), the area of maximum temperature (Tmax) was identified and compared to radiographs. A total of 31 patients were enrolled in the study. Twenty-four (77.50%) were identified as having fractures, and 7 (22.50%) did not have any fractures. IRT correctly identified an injury in the fracture group 91.67% of the time when using the Span and Level IRT image compared to standard x-rays (P < 0.0002). When using the Span and Level image to identify Tmax to localize a fracture on x-ray, sensitivity is 0.92, specificity is 0.86, positive predictive value is 0.96, and negative predictive value is 0.75. A receiver operating characteristic (ROC) curve was completed with area under the curve (AUC) being 0.89. This pilot study shows that the use of smart device infrared camera attachments is feasible and has promising results in fracture localization. This could allow for a decrease in radiographs and be particularly useful in resource-limited areas.

Impact of the COVID-19 pandemic on teaching and research activities in obstetrics and gynecology: a national two-stage, stratified, cluster sampling survey in China

BackgroundFew studies quantified the influence of the coronavirus disease 2019 (COVID-19) pandemic on medical teaching and scientific research activities in China. This is the first national study to investigate such topics from the viewpoint of physicians practicing obstetrics and gynecology in China.MethodsThis is a national questionnaire survey with online interviews for respondents. This two-stage, stratified, cluster sampling method was applied based on city categories (categories 1 to 3 correspond to < 10,000, 10,000 to 30,000, and > 30,000 beds, respectively), hospital levels (primary, secondary, and tertiary), and hospital types (general and specialized) in China among physicians practicing obstetrics and gynecology. Physicians documented notable alterations in both overall and specialized teaching and research engagements. Comparative analyses were conducted across diverse municipal and hospital attributes.ResultsData were collected from a representative sample of 11,806 physicians from 779 hospitals across 157 cities and 31 provinces. Notably, except for online seminars, a minimum reduction of 20% in both overall and specialized teaching and research activities was observed among physicians. Up to 61.7% (95% confidence interval 59.3–64.0) of physicians reported either a complete termination or a > 50% decline in resident training. Compared with category 1 cities and primary hospitals, category 3 cities and tertiary hospitals experienced greater reductions in items of resident or graduate education, visiting scholar, clinical trials, and laboratory studies (adjusted p values < 0.05), coupled with notable increases in online seminar participation (adjusted p values of 0.002 and < 0.001, respectively).ConclusionsAmidst the COVID-19 pandemic in China, activities requiring direct, face-to-face communication were more affected in resource-rich cities and general hospitals compared to resource-limited areas and specialized hospitals. Residency training experienced the most significant decline. Conversely, participation in online seminars increased, providing additional opportunities for continuing medical education.

Two-dimensional photonic crystal acetylcholinesterase hydrogel and organohydrogel sensors for efficient detection of organophosphorus compounds

Sensors capable of detecting organophosphorus (OP) compounds have attracted the most attention owing to severe OP contamination worldwide. Despite many years of research, the developed OP sensors mainly focused on detecting water-soluble OPs in proper environments and the exploration of OP sensors suitable in resource-limited areas is extremely challenging. Here, a simple two-dimensional photonic crystal (2D PC) hydrogel featuring capabilities of effectively quantitative determination of OP compounds is facilely constructed by immobilizing the enzyme acetylcholinesterase (AChE) onto a bovine serum albumin (BSA) protein hydrogel. Owing to the specific interaction between AChE and OP compounds, the OP compounds are easily bound to the hydrogel, triggering volume phase transition and resulting in apparent Debye diffraction ring variations. The resulting hydrogel sensors show a limit of detection (LoD) of 2.23 nM for trichlorfon and 0.07 nM for diethyl methylphosphonate (DMPP), respectively. On the basis of the hydrogel, a responsive organohydrogel is facilely fabricated utilizing a solvent exchange strategy to meet the requirements of applications in harsh environments and detection of the non-water-soluble OP compounds. The organohydrogel sensors, however, demonstrated a LoD of 0.70 μM for trichlorfon and 4.46 μM for DMPP, respectively. This work provides new light on the development of next-generation stable, low-cost, and portable field sensing devices.

A-354 Evaluating Emergent POC Technology for Sickle Cell Testing in Resource Limited Settings

Abstract Background Sickle cell disease (SCD) represents a collection of inherited hematological disorders characterized by abnormal sickle-shaped erythrocytes resulting in an increased risk of morbidity and mortality. SCD represents a significant global health burden, affecting more than 300,000 newborns per year. Most of these births occur in resource limited areas, including sub-Saharan Africa, where the mortality rate before the age of five is estimated to be as high as 50-80% and the existing infrastructure and resources cannot support most current and robust methods that offer hemoglobin variant detection and quantification for the diagnosis and monitoring of SCD. While newborn screening programs (NBS) to identify individuals affected with SCD have demonstrated efficacy in reducing morbidity and early mortality, NBS programs are limited outside of the US and Europe and face many practical challenges for universal implementation in a resource limited setting. The need for inexpensive and reliable hemoglobin variant detection and quantification at the Point of Care is essential to the diagnosis and management of SCD in resource limited settings with a high prevalence of SCD, and the expansion of NBS programs. This study aims to evaluate an inexpensive testing strategy using two methodologies for POC screening and confirmation of SCD that could be supported in a low resource setting. Methods The two-step testing strategy for evaluation of POC testing for hemoglobin variant detection and quantification included testing residual specimens from normal and known sickle cell patients by first screening with the HemoTypeSC, a qualitative lateral flow immunoassay (LFIA) that has improved sensitivity and specificity from other available LFIA methodologies given the use of monoclonal antibodies for the detection of hemoglobin variants. Confirmatory testing and quantification of hemoglobin variants was accomplished with the use of the Gazelle POC test a miniaturized chip-based cellulose acetate electrophoresis device capable of identification and quantification of normal and variant hemoglobin. Statistical evaluation of device performance and clinical agreement between the device and known disease status was achieved in EP evaluator. Results The two-tier testing strategy demonstrated effective and inexpensive mechanism for SCD screening and confirmation. Overall, the HemoTypeSC and Gazelle demonstrated 100% qualitative agreement between methods, with the total cost of the two-tiered testing strategy estimated at under $6 per sample. Conclusions In conclusion, the two-tiered approach using the HemoTypeSC and Gazelle yielded a practical and cost-effective strategy for screening and confirmation of hemoglobin variants for the detection and monitoring of SCD. Both the strip and chip-based methodologies provide rapid results, are accessible at the point-of-care, and require minimal sample volume, a feature ideal for use in a pediatric population in low resource settings. Overall, these methods show promise for the use and expansion of NBS programs to improve public health initiatives for the diagnosis of SCD.

Advances and Challenges Associated with Low-Cost Pulse Oximeters in Home Care Programs: A Review.

Oximeters have significantly evolved since their invention and are essential for monitoring chronic diseases in home care. However, commercial models can present an economic barrier. Therefore, we conducted a review of the use of low-cost pulse oximeters in the home care of patients with respiratory diseases. Our review included studies addressing oxygen saturation and heart rate monitoring in adults, focusing on the use of portable devices. Our search identified advances in vital signs monitoring that could provide accessible solutions for non-clinical settings. Although there are challenges related to clinical validation and accuracy, these oximeters may improve medical care, particularly in resource-limited areas. As a result, the accessibility of these devices opens up new possibilities for patients with chronic respiratory diseases in home care, enabling regular self-monitoring and increasing control over their health.

Seroprevalence of Schistosoma japonicum Infection Among Dogs and Water Buffaloes Using Recombinant Antigen ELISA in New Corella, Davao del Norte, Philippines.

Animal reservoirs are important targets for controlling and eliminating schistosomiasis. Prevalence studies showed that dogs (Canis familiaris) and water buffaloes (Bubalus bubalis) are important reservoirs of S. japonicum. Previous studies have validated the use of the recombinant proteins Sj1TR, Sj7TR, and SjTPx-1 in ELISA as diagnostics for dogs and water buffaloes from schistosomiasis-endemic areas. In this study, we aimed to determine the seroprevalence of S. japonicum among dogs and water buffaloes in New Corella, Davao del Norte, Philippines, using the recombinant proteins Sj1TR, Sj7TR, and SjTPx-1 in ELISA format. Fecal and serum samples were collected from dogs (n = 63) and water buffaloes (n = 57). Schistosome-positive samples were detected using formalin-ether concentration technique (FECT), stool polymerase chain reaction, and enzyme-linked immunosorbent assay (ELISA) using soluble egg antigen (SEA), rSj1TR, rSj7TR, and rSjTPx-1. Positivity rates, sensitivity, specificity, predictive values, accuracy, and kappa values were calculated. Mean positivity rates for schistosome infection were high for both dogs (x = 15.40%) and water buffaloes (x = 6.32%). On dogs, the sensitivity and specificity of the tests are as follows: 66.67% and 100% for rSj7TR-ELISA, while 100% and 93.33% for rSjTPx-1-ELISA, respectively. rSjTPx-1-ELISA showed the highest agreement with stool PCR among all diagnostic tests, with an overall kappa value of 0.824. On water buffaloes, the sensitivity and specificity of both rSj1TR-ELISA and rSjTPx-1-ELISA are 100.0% and 98.15%. Both tests also had an overall kappa value of 0.84. To ensure elimination and prevention of schistosomiasis in humans, the use of validated serological diagnostics such as recombinant antigen ELISA is preferable for field detection in animals, especially in resource-limited areas.

Peak expiratory flow rate monitoring can predict asthma exacerbation better as compared to monitoring by symptoms, prospective cohort study

Background: Global initiative for asthma (GINA) guidelines suggest to use peak expiratory flow rate (PEFR) monitoring to assess response to treatment, to identify triggers for exacerbation and to have a baseline value for action plan (especially for the poor perceivers). In comparison to adults, there are less evidence in support of the routine use of PEFR recording for the diagnosis and monitoring level of control of asthma in children. This study was conducted with objective to assess the effect of PEFR monitoring on numbers of exacerbations in comparison to monitoring by symptoms in asthma. Methods: This was a prospective cohort study done for a in department of pediatrics and respiratory medicine, of a tertiary care hospital, North India. Prior to recruitment ethical approval and informed consent/assent was taken. Study subjects were children with partial and uncontrolled asthma aged 5-12 years of age. Patients were divided into two groups on their first visit by using random allocation number. In group “A” monitoring was done with symptoms only, while in group “B” monitoring was done by symptoms and PEFR. Number of exacerbations during study period was noted. At baseline and follow up, CACT score was calculated. Spirometry was done at the end of 3 months. Results: Group B had statistically significant lesser exacerbation during study period as compared to group A (OR=0.23; 95% CI=0.06-0.81; p=0.020). Conclusions: PEFR based monitoring can be used as a potential tool for aborting or decreasing the severity of episodes of exacerbations of asthma especially in resource limited areas.

Fill, Fold, Photo: Preconcentration and Multiplex Detection of Trace Level Heavy Metals in Water.

Heavy metal contamination is an increasing global threat to human and environmental health, particularly in resource-limited areas. Traditional platforms for heavy metal detection are labor intensive and expensive and require lab facilities. While paper-based colorimetric sensors offer a simpler approach, their sensitivity limitations prevent them from meeting legislative requirements for many metals. Existing preconcentration systems, on the other hand, can achieve lower detection limits but typically focus on analyzing only one metal, making comprehensive monitoring difficult. We address these limitations by introducing a low-cost preconcentration system coupled with colorimetric analysis for the simultaneous detection of seven metal ions at low ppb levels without the need for external equipment outside a smartphone. The system achieved detection limits of 15 ppb (Ni(II)), 7 ppb (Cu(II)), 2 ppb (Fe(III)), 20 ppb (Cr(VI)), 13 ppb (Pb(II)), 26 ppb (Hg(II)), and 15 ppb (Mn(II)) with six out of seven limits of detection values falling well below EPA regulatory guidelines for drinking water. The user-friendly Fill, Fold, Photo approach eliminates complex pretreatment steps. Smartphone-based detection offers portable quantification within seconds. Employing masking strategies ensured higher selectivity for each assay on the card, while our packaging protocols enable system stability for over 4 weeks of study, facilitating mass production and deployment within a realistic time frame. To validate the sensor's performance in real-world scenarios, the sensor was tested with environmental water samples. The sensor demonstrated good recovery, ranging from 77% to 94% compared to the standard ICP-MS method. Furthermore, spike recovery analysis confirmed the sensor's accuracy, with a relative standard deviation (RSD) of less than 15%. This technology holds significant promise for future development as a convenient, portable solution for field-based monitoring of a broad spectrum of water contaminants, including pesticides, PFAS, fertilizers, and beyond.

Mobile Critical Care in Resource-Limited Settings: An Unmet Need.

Care of the critically ill in resource-limited areas, inside or outside the intensive care unit (ICU), is indispensable. Murthy and Adhikari noted that about 70% of patients in low-middle income (LMIC) areas could benefit from good critical care. Many patients in resource-limited settings still die before getting to the hospital. Investing in capacity building by strengthening and expanding ICU capability and training intensivists, critical care nurses, respiratory therapists, and other ICU staff is essential, but this process will take years. Also, having advanced healthcare facilities that are still far from remote areas will not do much to alleviate distance and mode of transportation as barriers to achieving good critical care. This paper discusses the importance of mobile critical care units (MCCUs) in supporting and enhancing existing emergency medical systems. MCCUs will be crucial in addressing critical delays in transportation and time to receive appropriate lifesaving critical care in remote areas. They are incredibly versatile and could be used to transfer severely ill patients to a higher level of care from the field, safely transfer critically ill patients between hospitals, and, sometimes, almost more importantly, provide standalone short-term critical care in regions where ICUs might be absent or immediately inaccessible. MCCUs should not be used as a substitute for primary care or to bypass readily available services at local healthcare centers. It is essential to rethink the traditional paradigm of 'prehospital care' and 'hospital care' and focus on improving the care of critically ill patients from the field to the hospital.

Multiplex detection of meningitis pathogens by a vertical flow paper microarray and signal enhancement suitable for low-resource settings: Proof of concept

ObjectivesMeningitis is a medical emergency, and it is crucial to diagnose it accurately and promptly in order to manage patients effectively. It would, therefore, be essential to introduce and have fast, accurate, and user-friendly methods to determine the cause of these infections. This study aimed to demonstrate a potentially cost-effective new approach for detecting meningitis using a paper-based vertical flow microarray, which could be useful in settings with limited resources. MethodsWe describe a multiplex paper microarray for detecting Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, and Salmonella spp. by the passive vertical flow of PCR-amplified clinical samples. A multibiotinylated amplicon was obtained as a product of PCR in the presence of both a biotinylated primer and biotin-11-dUTP. An enhancement step based on an enzyme-free gold enhancement protocol was also used to facilitate visual detection. ResultsThis study showed that the vertical flow microarray (previously evaluated for one pathogen) can discriminately detect the amplification results down to the 102 copies of DNA limit for four meningitis pathogens in a multiplexed set-up. The study further demonstrated the ability of this device and setup to detect three of the four pathogens from clinical biosamples. DiscussionThis study demonstrated the capacity of a vertical flow microarray device to detect amplification products for four prevalent meningitis pathogens in a multiplex format. The vertical flow microarray demonstrated consistent visualization of the expected gene amplification results; however, indicating limitations in the pre- and amplification steps. This study highlights the potential of this multiplexing method for diagnosing meningitis and other syndromic diseases caused by various pathogens, especially in resource-limited areas.

A Multi-Epitope Protein for High-Performance Serodiagnosis of Chronic Chagas Disease in ELISA and Lateral Flow Platforms.

We developed a protein to rapidly and accurately diagnose Chagas disease, a life-threatening illness identified by the WHO as a critical worldwide public health risk. Limitations in present day serological tests are complicating the current health situation and contributing to most infected persons being unaware of their condition and therefore untreated. To improve diagnostic testing, we developed an immunological mimic of the etiological agent, Trypanosoma cruzi, by combining ten pathogen-specific epitopes within the beta-barrel protein structure of Thermal Green Protein. The resulting multi-epitope protein, DxCruziV3, displayed high specificity and sensitivity as the antibody capture reagent in an ELISA platform with an analytical sensitivity that exceeds WHO recommendations. Within an immunochromatographic platform, DxCruziV3 showed excellent performance for the point of application diagnosis in a region endemic for multiple diseases, the municipality of Barcelos in the state of Amazonas, Brazil. In total, 167 individuals were rapidly tested using whole blood from a finger stick. As recommended by the Brazilian Ministry of Health, venous blood samples were laboratory tested by conventional assays for comparison. Test results suggest utilizing DxCruziV3 in different assay platforms can confidently diagnose chronic infections by T. cruzi. Rapid and more accurate results will benefit everyone but will have the most noticeable impact in resource-limited rural areas where the disease is endemic.